Aslamu aalekum sister. it is very scaring to see such a dreams. i wold like to sugeest you to Recite 4 Kul i.e Sureh Kaferun, Sureh Ikhlas, Sureh Falak & Sureh Naas 3 time each. then Recite Darood Sharif 10 Time, Istagfar once and at the end 4 times Aaytulkursi when u go to bed. Inshallah ur...